Need for Speed: Rivals will wow you initially, but there are too many missteps for it to keep you engaged for a sizeable length of time. The nonsensical story, surprising lack of features and an online component that may as well not be there overshadow the fantastic driving mechanics and lead to a rather monotonous game.
XCOM: Enemy Within is the definitive XCOM experience. There's enough here to keep veterans of the series engaged for another playthrough and it's a perfect launching point for newcomers to experience what may be the best turn-based strategy game on the market right now.
X Rebirth is a broken game right now. The UI is clunky, flying feels awkward at best, and you're often left to figure out how to play without any real sort of guidance. This could end up being a fine game once modders are able to essentially remake it, but there's no real reason to pick it up at the current moment.
Lords of Shadow 2 had limitless potential in front of it, and could have been the best Castlevania game of recent memory, but poor design choices, a questionable story and flawed mechanics will kill most players' interest before they even get half-way through.
Dark Souls II is absolutely devious and won't hesitate to punish you for your mistakes, but the feeling of accomplishment that comes from making progress is unmatched by anything else on the market. It's not a game that will cater to every player's wants, but if you're the type who enjoys a challenge, this is absolutely a must play.